Data were obtained from admission records and two face- to-face interviews conducted in 1974-75 and 1985-86. The interviews collected information on patterns of drug use and related questions that covered successive periods of the addiction career from 1 year prior to first narcotics use to 1974-75 for the first interview and from 1970 to 1985-86 for the second interview. The majority of the sample began narcotics use before age 20 and had a mean age at program admission of 25.4. In 1974-75 13.8 percent of the sample had died, and 28.6 percent tested negative for opiates. Corresponding rates in 1985-86 were 27.7 percent and 25.0 percent. Substance use and criminal involvement remained high among this sample into their late forties. The findings suggest that the eventual cessation of narcotics use is a slow process, unlikely to occur for some addicts, especially if they have not ceased use by their late thirties. 21 references, 4 tables, and 1 figure